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		<h1>Input Class</h1>

		<p>The Input Class serves two purposes:</p>

		<ol>
			<li>It pre-processes global input data for security.</li>
			<li>It provides some helper functions for fetching input data
				and pre-processing it.</li>
		</ol>

		<p class="important">
			<strong>Note:</strong> This class is initialized automatically by the
			system so there is no need to do it manually.
		</p>


		<h2>Security Filtering</h2>

		<p>
			The security filtering function is called automatically when a new <a
				href="../general/controllers.html">controller</a> is invoked. It
			does the following:
		</p>

		<ul>
			<li>If $config['allow_get_array'] is FALSE(default is TRUE),
				destroys the global GET array.</li>
			<li>Destroys all global variables in the event register_globals
				is turned on.</li>
			<li>Filters the GET/POST/COOKIE array keys, permitting only
				alpha-numeric (and a few other) characters.</li>
			<li>Provides XSS (Cross-site Scripting Hacks) filtering. This
				can be enabled globally, or upon request.</li>
			<li>Standardizes newline characters to \n(In Windows \r\n)</li>
		</ul>


		<h2>XSS Filtering</h2>

		<p>
			The Input class has the ability to filter input automatically to
			prevent cross-site scripting attacks. If you want the filter to run
			automatically every time it encounters POST or COOKIE data you can
			enable it by opening your
			<kbd>application/config/config.php</kbd>
			file and setting this:
		</p>

		<code>$config['global_xss_filtering'] = TRUE;</code>

		<p>
			Please refer to the <a href="security.html">Security class</a>
			documentation for information on using XSS Filtering in your
			application.
		</p>


		<h2>Using POST, COOKIE, or SERVER Data</h2>

		<p>CodeIgniter comes with three helper functions that let you
			fetch POST, COOKIE or SERVER items. The main advantage of using the
			provided functions rather than fetching an item directly
			($_POST['something']) is that the functions will check to see if the
			item is set and return false (boolean) if not. This lets you
			conveniently use data without having to test whether an item exists
			first. In other words, normally you might do something like this:</p>

		<code>
			if ( ! isset($_POST['something']))<br /> {<br />
			&nbsp;&nbsp;&nbsp;&nbsp;$something = FALSE;<br /> }<br /> else<br />
			{<br /> &nbsp;&nbsp;&nbsp;&nbsp;$something = $_POST['something'];<br />
			}
		</code>

		<p>With CodeIgniter's built in functions you can simply do this:</p>

		<code>$something = $this->input->post('something');</code>

		<p>The three functions are:</p>

		<ul>
			<li>$this->input->post()</li>
			<li>$this->input->cookie()</li>
			<li>$this->input->server()</li>
		</ul>

		<h2>$this->input->post()</h2>

		<p>The first parameter will contain the name of the POST item you
			are looking for:</p>

		<code>$this->input->post('some_data');</code>

		<p>The function returns FALSE (boolean) if the item you are
			attempting to retrieve does not exist.</p>

		<p>The second optional parameter lets you run the data through the
			XSS filter. It's enabled by setting the second parameter to boolean
			TRUE;</p>

		<code>$this->input->post('some_data', TRUE);</code>

		<p>To return an array of all POST items call without any
			parameters.</p>
		<p>To return all POST items and pass them through the XSS filter
			set the first parameter NULL while setting the second parameter to
			boolean;</p>
		<p>The function returns FALSE (boolean) if there are no items in
			the POST.</p>

		<code>
			$this->input->post(NULL, TRUE); // returns all POST items with XSS
			filter <br /> $this->input->post(); // returns all POST items
			without XSS filter
		</code>

		<h2>$this->input->get()</h2>

		<p>This function is identical to the post function, only it
			fetches get data:</p>

		<code>$this->input->get('some_data', TRUE);</code>

		<p>To return an array of all GET items call without any
			parameters.</p>
		<p>To return all GET items and pass them through the XSS filter
			set the first parameter NULL while setting the second parameter to
			boolean;</p>
		<p>The function returns FALSE (boolean) if there are no items in
			the GET.</p>

		<code>
			$this->input->get(NULL, TRUE); // returns all GET items with XSS
			filter <br /> $this->input->get(); // returns all GET items without
			XSS filtering
		</code>

		<h2>$this->input->get_post()</h2>

		<p>This function will search through both the post and get streams
			for data, looking first in post, and then in get:</p>

		<code>$this->input->get_post('some_data', TRUE);</code>

		<h2>$this->input->cookie()</h2>

		<p>This function is identical to the post function, only it
			fetches cookie data:</p>

		<code>$this->input->cookie('some_data', TRUE);</code>

		<h2>$this->input->server()</h2>

		<p>This function is identical to the above functions, only it
			fetches server data:</p>

		<code>$this->input->server('some_data');</code>


		<h2>$this->input->set_cookie()</h2>

		<p>Sets a cookie containing the values you specify. There are two
			ways to pass information to this function so that a cookie can be
			set: Array Method, and Discrete Parameters:</p>

		<h4>Array Method</h4>

		<p>Using this method, an associative array is passed to the first
			parameter:</p>

		<code>
			$cookie = array(<br />
			&nbsp;&nbsp;&nbsp;&nbsp;'name'&nbsp;&nbsp;&nbsp;=> 'The Cookie Name',<br />
			&nbsp;&nbsp;&nbsp;&nbsp;'value'&nbsp;&nbsp;=> 'The Value',<br />
			&nbsp;&nbsp;&nbsp;&nbsp;'expire' => '86500',<br />
			&nbsp;&nbsp;&nbsp;&nbsp;'domain' => '.some-domain.com',<br />
			&nbsp;&nbsp;&nbsp;&nbsp;'path'&nbsp;&nbsp;&nbsp;=> '/',<br />
			&nbsp;&nbsp;&nbsp;&nbsp;'prefix' => 'myprefix_',<br />
			&nbsp;&nbsp;&nbsp;&nbsp;'secure' => TRUE<br /> );<br /> <br />
			$this->input->set_cookie($cookie);
		</code>

		<p>
			<strong>Notes:</strong>
		</p>

		<p>Only the name and value are required. To delete a cookie set it
			with the expiration blank.</p>

		<p>
			The expiration is set in <strong>seconds</strong>, which will be
			added to the current time. Do not include the time, but rather only
			the number of seconds from <em>now</em> that you wish the cookie to
			be valid. If the expiration is set to zero the cookie will only last
			as long as the browser is open.
		</p>
		<p>
			For site-wide cookies regardless of how your site is requested, add
			your URL to the <strong>domain</strong> starting with a period, like
			this: .your-domain.com
		</p>
		<p>The path is usually not needed since the function sets a root
			path.</p>
		<p>The prefix is only needed if you need to avoid name collisions
			with other identically named cookies for your server.</p>
		<p>The secure boolean is only needed if you want to make it a
			secure cookie by setting it to TRUE.</p>

		<h4>Discrete Parameters</h4>

		<p>If you prefer, you can set the cookie by passing data using
			individual parameters:</p>

		<code>$this->input->set_cookie($name, $value, $expire, $domain,
			$path, $prefix, $secure);</code>

		<h2>$this->input->cookie()</h2>

		<p>Lets you fetch a cookie. The first parameter will contain the
			name of the cookie you are looking for (including any prefixes):</p>

		<code>cookie('some_cookie');</code>

		<p>The function returns FALSE (boolean) if the item you are
			attempting to retrieve does not exist.</p>

		<p>The second optional parameter lets you run the data through the
			XSS filter. It's enabled by setting the second parameter to boolean
			TRUE;</p>

		<p>
			<code>cookie('some_cookie', TRUE);</code>
		</p>


		<h2>$this->input->ip_address()</h2>
		<p>Returns the IP address for the current user. If the IP address
			is not valid, the function will return an IP of: 0.0.0.0</p>
		<code>echo $this->input->ip_address();</code>


		<h2>
			$this->input->valid_ip(
			<var>$ip</var>
			)
		</h2>

		<p>Takes an IP address as input and returns TRUE or FALSE
			(boolean) if it is valid or not. Note: The $this->input->ip_address()
			function above validates the IP automatically.</p>

		<code>
			if ( ! $this-&gt;input-&gt;valid_ip($ip))<br /> {<br />
			&nbsp;&nbsp;&nbsp;&nbsp; echo 'Not Valid';<br /> }<br /> else<br />
			{<br /> &nbsp;&nbsp;&nbsp;&nbsp; echo 'Valid';<br /> }
		</code>
		<p>Accepts an optional second string parameter of "IPv4" or "IPv6"
			to specify an IP format. The default checks for both formats.</p>

		<h2>$this->input->user_agent()</h2>
		<p>Returns the user agent (web browser) being used by the current
			user. Returns FALSE if it's not available.</p>
		<code>echo $this->input->user_agent();</code>
		<p>
			See the <a href="user_agent.html">User Agent Class</a> for methods
			which extract information from the user agent string.
		</p>

		<h2>$this->input->request_headers()</h2>
		<p>
			Useful if running in a non-Apache environment where <a
				href="http://php.net/apache_request_headers">apache_request_headers()</a>
			will not be supported. Returns an array of headers.
		</p>

		<code>$headers = $this->input->request_headers();</code>

		<h2>$this->input->get_request_header();</h2>
		<p>Returns a single member of the request headers array.</p>

		<code>$this->input->get_request_header('some-header', TRUE);</code>


		<h2>$this->input->is_ajax_request()</h2>
		<p>
			Checks to see if the
			<var>HTTP_X_REQUESTED_WITH</var>
			server header has been set, and returns a boolean response.
		</p>


		<h2>$this->input->is_cli_request()</h2>
		<p>
			Checks to see if the
			<var>STDIN</var>
			constant is set, which is a failsafe way to see if PHP is being run
			on the command line.
		</p>

		<code>$this->input->is_cli_request()</code>


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